Comparative study between the effect of the peroxisome proliferator activated receptor-α ligands fenofibrate and n-3 polyunsaturated fatty acids on activation of 5′-AMP-activated protein kinase-α1 in high-fat fed rats

2009 ◽  
Vol 61 (10) ◽  
pp. 1339-1346 ◽  
Author(s):  
Tarek M. Kamal Motawi ◽  
Reem M. Hashem ◽  
Laila A. Rashed ◽  
Sabry M. Abd El-Razek
Keyword(s):  
Fatty Acids ◽  
Protein Kinase ◽  
Polyunsaturated Fatty Acids ◽  
Comparative Study ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Amp Activated Protein Kinase

Epinephrine and AICAR-induced PGC-1α mRNA expression is intact in skeletal muscle from rats fed a high-fat diet

2012 ◽  
Vol 302 (12) ◽  
pp. C1772-C1779 ◽  
Author(s):  
Bruce C. Frier ◽  
Zhongxiao Wan ◽  
Deon B. Williams ◽  
Amanda L. Stefanson ◽  
David C. Wright
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
High Fat Diet ◽  
Camp Response Element Binding ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Male Wistar Rats ◽  
Amp Activated Protein Kinase

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a master regulator of mitochondrial biogenesis and is controlled, at least in part, through AMP-activated protein kinase and p38-dependent pathways. There is evidence demonstrating that activation of these kinases and induction of PGC-1α in skeletal muscle are regulated by catecholamines. The purpose of the present study was to determine if consumption of a high-fat diet (HFD) impairs epinephrine and 5-aminoimidazole-4-carboxamide-1β-d-ribofuranoside (AICAR) signaling and induction of PGC-1α in rat skeletal muscle. Male Wistar rats were fed chow or a HFD for 6 wk and then given a weight-adjusted bolus injection of epinephrine (20, 10, or 5 μg/100 g body wt sc) or saline, and triceps muscles were harvested 30 min (signaling) or 2 and 4 h (gene expression) postinjection. Despite blunted increases in p38 phosphorylation, the ability of epinephrine to induce PGC-1α was intact in skeletal muscle from HFD-fed rats and was associated with normal increases in activation of PKA and phosphorylation of cAMP response element-binding protein, reputed mediators of PGC-1α expression. The attenuated epinephrine-mediated increase in p38 phosphorylation was independent of increases in MAPK phosphatase 1. At 2 h following AICAR treatment (0.5 g/kg body wt sc), AMP-activated protein kinase and acetyl-CoA carboxylase phosphorylation were similar in skeletal muscle from chow- and HFD-fed rats. Surprisingly, AICAR-induced increases in PGC-1α mRNA levels were greater in skeletal muscle from HFD-fed rats. Our results demonstrate that the ability of epinephrine and AICAR to induce PGC-1α remains intact in skeletal muscle from HFD-fed rats. These results question the existence of reduced β-adrenergic responsiveness in diet-induced obesity and demonstrate that increases in p38 phosphorylation are not required for induction of PGC-1α in muscle from obese rats.

scholarly journals Peroxisome Proliferator-Activated Receptor γ Coactivator 1α and FoxO3A Mediate Chondroprotection by AMP-Activated Protein Kinase

2014 ◽  
Vol 66 (11) ◽  
pp. 3073-3082 ◽  
Author(s):  
Xianling Zhao ◽  
Freyr Petursson ◽  
Benoit Viollet ◽  
Martin Lotz ◽  
Robert Terkeltaub ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Amp Activated Protein Kinase
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